问题
Constraints: I'm not using MVC, just regular ol' .aspx files in my web app. Not using master pages either - each page is a different beast, so that solution isn't right for me.
Most examples I've read for bundling and minification require either some special MVC markup or require you to identify the bundled scripts / stylesheets up front and then refer to these bundles. I want to avoid recompiling DLLs every time I add or modify a .js reference in a .aspx page.
I'm a bit stumped from reading the Msft docs.. is there a way (like an ASP.NET control) that I can just wrap a series of script tags (or link tags for CSS) to create and use a bundle dynamically? I don't want to reinvent the wheel, but seriously considering creating my own user control / custom control that handles this. Are there other options?
For example, looking for something like this:
<asp:AdHocScriptBundle id="mypage_bundle" runat="server">
<script type="text/javascript" src="~/scripts/mypage1.js"></script>
<script type="text/javascript" src="~/scripts/mypage2.js"></script>
<script type="text/javascript" src="~/scripts/mypage3.js"></script>
</asp:AdHocScriptBundle>
that, when bundling is enabled, automatically replaces the contents of asp:AdHocScriptBundle with a single script tag that resembles this:
<script type="text/javascript" src="/webappname/bundles/mypage_bundle.js?v=dh120398dh1298dh192d8hd32d"></script>
And when Bundling is disabled, outputs the contents normally like this:
<script type="text/javascript" src="/webappname/scripts/mypage1.js"></script>
<script type="text/javascript" src="/webappname/scripts/mypage2.js"></script>
<script type="text/javascript" src="/webappname/scripts/mypage3.js"></script>
Any thoughts?
About to roll my own anyway, but if there is already a solution for this please share, thanks!
回答1:
I rolled my own solution and it works great! I created 4 classes that I can use as custom server controls:
- ScriptBundle
- Script
- StyleBundle
- Link
These call functions around my custom bundling library which is itself a wrapper for the System.Web.Optimization API.
During Render of ScriptBundle and StyleBundle I then check an internal setting (the same one that I use to set EnableOptimizations in the System.Web.Optimization API) that tells the page to either use bundling, or simply write out the normal script / link tags. If Bundling is enabled it calls this function from my custom bundling library (for Scripts, similar code for Styles tho. Bundler in code below is the class for my custom bundling library - just in case Microsoft changes the System.Web.Optimization API I wanted a layer in-between so that I wouldn't have to change my code as much):
public static void AddScriptBundle(string virtualTargetPath, params string[] virtualSourcePaths)
{
var scriptBundle = new System.Web.Optimization.ScriptBundle(virtualTargetPath);
scriptBundle.Include(virtualSourcePaths);
System.Web.Optimization.BundleTable.Bundles.Add(scriptBundle);
}
To make sure that I only create the Bundle if it does not already exist, I first check for the Bundle using this method (before using the above method):
public static bool BundleExists(string virtualTargetPath)
{
return System.Web.Optimization.BundleTable.Bundles.GetBundleFor(virtualTargetPath) != null;
}
Then I use this function to spit out the URL to the bundle by using System.Web.Optimization:
public static System.Web.IHtmlString GetScriptBundleHTML(string virtualTargetPath)
{
return System.Web.Optimization.Scripts.Render(virtualTargetPath);
}
Within my .aspx files, I do this:
<%@ Register TagPrefix="cc1" Namespace="AdHocBundler" Assembly="AdHocBundler" %>
...
<cc1:ScriptBundle name="MyBundle" runat="Server">
<cc1:script src='~/js/script1.js'/>
<cc1:script src='~/js/utils/script2.js'/>
</cc1:ScriptBundle>
The trick for me was figuring out that I had to convert script and link tags to be work as list items within the ScriptBundle and StyleBundle controls, but after that it works great AND it let me use the tilde operator for easy references relative to app root (using Page.ResolveClientUrl(), which is helpful for creating module content).
Thanks go to this SO answer for helping me figure out how to create a custom collection control: How do you build an ASP.NET custom control with a collection property?
UPDATE: In the interest of full disclosure, I got permission to share the code for ScriptBundle (StyleBundle is almost identical, so did not include it):
[DefaultProperty("Name")]
[ParseChildren(true, DefaultProperty = "Scripts")]
public class ScriptBundle : Control
{
public ScriptBundle()
{
this.Enabled = true;
this.Scripts = new List<Script>();
}
[PersistenceMode(PersistenceMode.Attribute)]
public String Name { get; set; }
[PersistenceMode(PersistenceMode.Attribute)]
[DefaultValue(true)]
public Boolean Enabled { get; set; }
[PersistenceMode(PersistenceMode.InnerDefaultProperty)]
public List<Script> Scripts { get; set; }
protected override void Render(HtmlTextWriter writer)
{
if (String.IsNullOrEmpty(this.Name))
{
// Name is used to generate the bundle; tell dev if he forgot it
throw new Exception("ScriptBundle Name is not defined.");
}
writer.BeginRender();
if (this.Enabled && Bundler.EnableOptimizations)
{
if (this.Scripts.Count > 0)
{
string bundleName = String.Format("~/bundles{0}/{1}.js",
HttpContext.Current.Request.FilePath,
this.Name).ToLower();
// create a bundle if not exists
if (!Bundler.BundleExists(bundleName))
{
string[] scriptPaths = new string[this.Scripts.Count];
int len = scriptPaths.Length;
for (int i = 0; i < len; i++)
{
if (!string.IsNullOrEmpty(this.Scripts[i].Src))
{
// no need for resolve client URL here - bundler already does it for us, so paths like "~/scripts" will already be expanded
scriptPaths[i] = this.Scripts[i].Src;
}
}
Bundler.AddScriptBundle(bundleName, scriptPaths);
}
// spit out a reference to bundle
writer.Write(Bundler.GetScriptBundleHTML(bundleName));
}
}
else
{
// do not use bundling. generate normal script tags for each Script
foreach (Script s in this.Scripts)
{
if (!string.IsNullOrEmpty(s.Src))
{
// render <script type='<type>' src='<src'>/> ... and resolve URL to expand tilde, which lets us use paths relative to app root
// calling writer.Write() directly since it has less overhead than using RenderBeginTag(), etc., assumption is no special/weird chars in the cc1:script attrs
writer.Write(String.Format(Script.TAG_FORMAT_DEFAULT,
s.Type,
Page.ResolveClientUrl(s.Src)));
}
}
}
writer.EndRender();
}
}
public class Script
{
public const String ATTR_TYPE_DEFAULT = "text/javascript";
public const String TAG_FORMAT_DEFAULT = "<script type=\"{0}\" src=\"{1}\"></script>";
public Script()
{
this.Type = ATTR_TYPE_DEFAULT;
this.Src = null;
}
public String Type { get; set; }
public String Src { get; set; }
public String Language { get; set; }
}
回答2:
This isn't possible with the default Bundling/Minification in ASP.NET. The entire point of bundling is to create one single to file to reduce the number of browser requests to load static files such as .JS and .CSS files.
Rolling your own is your only option. However, please note that each <script> line will result in a browser request. Since most browsers can only handle 6 requests concurrently, you can have wait times just to load these static files.
And FYI, you don't have to recompile DLLs every time you update your .JS files with built-in bundling. You can simply reset the application pool the app is running on. If you're running with an external session persistence model, your users won't notice when this happens.
回答3:
Your problem here is that you aren't really thinking this problem through. If you were, you would realize that what you are asking for can't work.
Why? Because the script tag ahs to generate an external link reference to a different url. So anything you place in the header of the current file will have no affect on your other URL that actually contains your bundles. As such, there is no way to dynamically change your bundles in the page itself because bundles have to, by definition, be defined in an external resource.
Now, there's nothing that says those bundles have to be compiled into DLL's in your own solution, but they cannot be embedded in the page that's currently being rendered.
You might want to investigate some of the javascript based minification tools out there, since they are typically not compiled.
来源：https://stackoverflow.com/questions/17437800/how-do-i-use-asp-net-bundling-and-minification-without-recompiling